An injector pulse width monitoring circuit

2015-01-21 22:59

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This article introduces the monitoring is a fuel injector pulse width circuit principle. The components used in the circuit diagram with LM3914 , MM3906, CD4066, D1N914, LM324 and so on. Understanding these components will be more conducive to understanding the circuit diagram. First of all you see is a picture of faceplate, have LEDbargraphs air/fuel and pulse width, and can control the fuel mixture is higher than 7 psi of ascension a picture. The panel is made up of polished aluminium. Air/fuel (O2), pulse width and fuel monitoring controller display, a printed circuit board. Below is the principle of pulse width monitoring. The core circuit of current source transistor cost limit, form an integrator C10. This theory is that the cap was accused and voltage linearly increase the time, injector energizing. As jet off, voltage in C10 C9 is stored in the cap and then C10 reset to 0 v to prepare for the next cycle. The cap C9 is voltage output circuit, the voltage value is directly input U3 bar graph display chip betw1een 1-10 of leds. Potentiometer R31 setup charge rate in C10 and basic setup Max syringe in time can be displayed. In the calibration of the circuit is tricky. You need an oscilloscope and waveform generator. Set a 62 hz 0-12 v 50% duty cycle square wave circuit at the input. Using range monitoring voltage pot R31 C10 adjustment, increase the voltage C10 to peak (started to smooth). Now adjust the pot so that lead to 10 to R22 in display circuit. Calibration described above lead to approximately 1.5 ms and 1 LED 10 corresponding to 8 milliseconds injector pulse width (on time). Ejector working cycle depends on the engine speed according to the following relationship: % = work cycle (pulse width/period) * 100 = 1 / (engine speed (RPM) / 60].